Aircraft main engines not only provide propulsion for the aircraft, but in many instances may also be used to drive various other rotating components such as, for example, generators, compressors, and pumps, to thereby supply electrical, pneumatic, and/or hydraulic power. Generally, a gas turbine engine includes a combustor, a power turbine, and a compressor. During operation of the engine, the compressor draws in ambient air, compresses it, and supplies compressed air to the combustor. The compressor also typically includes a diffuser that diffuses the compressed air before it is supplied to the combustor. The combustor receives fuel from a fuel source and the compressed air from the compressor, and supplies high energy combustion gases to the power turbine, causing it to rotate. The power turbine includes a shaft that may be used to drive the compressor.
In some instances, an engine may additionally include a starter-generator, which may either drive the turbine or be driven by the turbine, via the turbine output shaft. Some engines additionally include a bleed air port between the compressor section and the turbine section. The bleed air port allows some of the compressed air from the compressor section to be diverted away from the turbine section, and used for other functions such as, for example, main engine starting air, environmental control, and/or cabin pressure control.
Gas turbine engines are constructed using one of several different bearing architectures. In one type of engine architecture, namely the popular “mid-sump” architecture, a bearing cavity, often referred to as a “sump”, is housed in proximity to the combustor near the middle of the engine. The bearing cavity, or sump, relies on service routings to supply various services such as air and oil thereto.
Although most engines, such as those generally described above, are robust, safe, and reliable, some engines do suffer certain drawbacks. For example, in certain mid-sump engines having compressors with radial vane diffusers, it may be difficult to supply air or oil service, electrical service for sensors, or other types of service to a bearing cavity or other region within the engine without crossing the air flow path within the diffuser. It is may also be difficult to structurally tie the bearing cavity to other structures of the engine.
Accordingly, there is a need for an improved system for providing oil and air service, and/or other types of service, to an engine with a radial vane diffuser without crossing the air flow path within the diffuser. The present invention addresses one or more of these needs.